ladybird/AK/Iterator.h

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/*
* Copyright (c) 2020, the SerenityOS developers.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/Forward.h>
namespace AK {
template<typename Container, typename ValueType>
class SimpleIterator {
public:
friend Container;
constexpr bool is_end() const { return m_index == SimpleIterator::end(m_container).m_index; }
constexpr size_t index() const { return m_index; }
constexpr bool operator==(SimpleIterator other) const { return m_index == other.m_index; }
constexpr bool operator!=(SimpleIterator other) const { return m_index != other.m_index; }
constexpr bool operator<(SimpleIterator other) const { return m_index < other.m_index; }
constexpr bool operator>(SimpleIterator other) const { return m_index > other.m_index; }
constexpr bool operator<=(SimpleIterator other) const { return m_index <= other.m_index; }
constexpr bool operator>=(SimpleIterator other) const { return m_index >= other.m_index; }
constexpr SimpleIterator operator+(ptrdiff_t delta) const { return SimpleIterator { m_container, m_index + delta }; }
constexpr SimpleIterator operator-(ptrdiff_t delta) const { return SimpleIterator { m_container, m_index - delta }; }
constexpr ptrdiff_t operator-(SimpleIterator other) const { return static_cast<ptrdiff_t>(m_index) - other.m_index; }
constexpr SimpleIterator operator++()
{
++m_index;
return *this;
}
constexpr SimpleIterator operator++(int)
{
++m_index;
return SimpleIterator { m_container, m_index - 1 };
}
constexpr SimpleIterator operator--()
{
--m_index;
return *this;
}
constexpr SimpleIterator operator--(int)
{
--m_index;
return SimpleIterator { m_container, m_index + 1 };
}
ALWAYS_INLINE constexpr const ValueType& operator*() const { return m_container[m_index]; }
ALWAYS_INLINE constexpr ValueType& operator*() { return m_container[m_index]; }
constexpr const ValueType* operator->() const { return &m_container[m_index]; }
constexpr ValueType* operator->() { return &m_container[m_index]; }
private:
static constexpr SimpleIterator begin(Container& container) { return { container, 0 }; }
static constexpr SimpleIterator end(Container& container)
{
using RawContainerType = typename RemoveCV<Container>::Type;
if constexpr (IsSame<StringView, RawContainerType>::value || IsSame<String, RawContainerType>::value)
return { container, container.length() };
else
return { container, container.size() };
}
constexpr SimpleIterator(Container& container, size_t index)
: m_container(container)
, m_index(index)
{
}
Container& m_container;
size_t m_index;
};
}